CN1287544C - Device for using OFDM diversity reception, OFDM receiving circuit and OFDM reception method - Google Patents
Device for using OFDM diversity reception, OFDM receiving circuit and OFDM reception method Download PDFInfo
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- CN1287544C CN1287544C CN200410087904.9A CN200410087904A CN1287544C CN 1287544 C CN1287544 C CN 1287544C CN 200410087904 A CN200410087904 A CN 200410087904A CN 1287544 C CN1287544 C CN 1287544C
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/0224—Channel estimation using sounding signals
- H04L25/0228—Channel estimation using sounding signals with direct estimation from sounding signals
- H04L25/023—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols
- H04L25/0232—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols by interpolation between sounding signals
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
- H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
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Abstract
The OFDM receiver includes: transform means (28A, 28B) having at least two systems (systems A, B) and transforming the received OFDM signal from antennas 24A, 24B for receiving the OFDM signal to a carrier domain signal per symbol unit; and a composite means (29) that segments the carrier units and adaptively composites the signal data which constitute a plurality of different carriers (frequencies) transformed by a first system (system A) transform means (28A) and the signal data which constitute a plurality of different carriers (frequencies) transformed by a second system (system B) transform means (28B) for each identical carrier (frequency) in each system.
Description
Technical field
The present invention relates to OFDM receiving system, OFDM receiving circuit and OFDM method of reseptance, particularly a kind of use can reduce error rate, improves OFDM receiving system, OFDM receiving circuit and the OFDM method of reseptance of the diversity of receiving quality.
Background technology
OFDM (Orthogonal Frequency Division Multiplexing: be a kind of in transmission bandwidth OFDM), between mutual interference not to take place is that principle is provided with a plurality of carrier waves as much as possible, give the amplitude and the phase assignments data of each carrier wave, carry out the transmission technology of PSK (Phase Shift Keying) or QAM digital modulation such as (Quadrature Amplitude Modulation).For example in the standard of Ri Ben ground-wave digital broadcasting (ISDB-T:Integrated Services DigitalBroadcasting-Terrestrial), in each broadcasting station, the bandwidth division that will be about 6MHz is 13 sections, the a plurality of carrier waves of orthogonal multiplex on each section carry out HDTV (high definition television) broadcasting, SDTV (standard television) broadcasting and to the simple and easy broadcasting of mobile thing etc.
In addition, from before since in order to improve receptivity, receiving system adopts diversity mode.In this mode, receive the electric wave that the radio station sent, the received signal of these a plurality of antennas is carried out the synthetic processing of maximum, select the highest signal of receiving quality (C/N) and output by combiner circuit by a plurality of antennas.The signal transformation that this receiving quality is the highest becomes digital signal, and carries out demodulation process in demodulator circuit.Like this, make the minimum that influences of decay in the transmission way etc.
Yet, in the above-mentioned former diversity mode, owing to carry out diversity, particularly in the mansion in the city etc. in the recurrent multipath state according to the signal of time zone, existence can't obtain enough receiving qualities, thus received this problem of data of demodulation accurately and reliably.
Summary of the invention
Therefore, the present invention's signal that a plurality of antennas are received carries out FFT in circuit separately handles, and this FFT is handled signal afterwards synthesize processing.
So just can reduce error rate and improve receiving quality, the data that demodulation accurately and reliably is received.
Description of drawings
Fig. 1 is the block diagram of the OFDM receiving system 23 of the use diversity among conceptual illustration the present invention.
The schematic diagram of the OFDM carrier wave regional signal that Fig. 2 is exported for FFT portion 28A, the 28B of explanation among the present invention.
Fig. 3 A makes a living into the block diagram of synthetic portion 29 of composite signal of the output signal of the output signal of the A system among the present invention and B system.
Fig. 3 B is the schematic diagram of the action of the 1st carrier filter 35 among explanation the present invention and the 2nd carrier filter 36.
Fig. 4 is the concept map of the action of the synthetic portion 29 among explanation the present invention.
Fig. 5 A is the effect key diagram of embodiments of the present invention.
Fig. 5 B is the effect key diagram of embodiments of the present invention.
Embodiment
The contrast accompanying drawing describes embodiments of the present invention below.In addition, to other the illustration of mark such as the specific and even example of each thin portion, numerical value, character string, only be the reference that provides in order to understand thought of the present invention in the following explanation, can not according to its all or a part limit thought of the present invention.In addition, for known method, in proper order, structure and circuit structure etc. (hereinafter to be referred as " known item ") omitted the explanation in this thin portion, simultaneously also be consideration, and be not to have a mind to get rid of all or part of of these known items for the simplicity of explanation.Because the related known item can be learnt by those skilled in the art before the applying date of the present invention, therefore comprised in the following description certainly.
Fig. 1 is for being applicable to the present invention the conceptual block diagram of the resulting OFDM receiving system 23 of ground-wave digital broadcasting transmitter.Among the figure, OFDM receiving system 23 is by the circuit part of these two systems of the 20B of circuit part of the 20A of circuit part of A system and B system, and the A system that is constituted with synthetic portion 29, error correcting unit 30, mpeg decode portion 31, audio frequency and video separated part 32, video decode portion 33 and audio decoder portion 34 and the omnibus circuit portion of B system constitute.The A system is identical with the structure of B system, the A system is made of antenna 24A, tuner 25A, A/D transformation component 26A, the 27A of quadrature demodulation portion and the 28A of FFT portion, the B system is made of antenna 24B, tuner 25B, A/D transformation component 26B, the 27B of quadrature demodulation portion and the 28B of FFT portion too.
The ofdm signal that the radio station sent that does not show among the figure is received by two antenna 24A, 24B, offers tuner 25A, the 25B of each system as high-frequency signal (RF signal).High-frequency signal is transformed into given intermediate-freuqncy signal (IF signal: the IntermediateFrequency signal) afterwards, be transformed into digital signal by A/D transformation component 26A, 26B by each tuner 25A, 25B.This digital signal is sent to the 27A of quadrature demodulation portion, 27B, carries out quadrature demodulation by the 27A of this quadrature demodulation portion, 27B and handles, and makes it to become again the carrier signal before the quadrature modulation processing is carried out in the radio station.Signal after the quadrature demodulation is the signal (OFDM symbol area signal) in symbol (symbol) zone (time zone) before the FFT computing.In addition, OFDM symbol area signal is by carrying out quadrature demodulation, become containing the complex signal of real axis composition (I channel signal) and imaginary axis composition (Q channel signal).
Next, OFDM symbol area signal is sent to the 28A of FFT portion, 28B, is transformed into carrier wave zone (frequency field) signal (OFDM carrier wave regional signal) that signal data constituted of a plurality of different carrier waves by the 28A of this FFT portion, 28B.The 28A of FFT portion, 28B extract out from each carrier wave by the data of quadrature modulation and output, specifically, the 28A of FFT portion, 28B, from an OFDM symbol, extract the long scope of significant character out, scope (for example 2048 sampling) also promptly extracting out from an OFDM symbol except between the boot section is carried out the FFT computing to the OFDM symbol area signal of this scope.Like this, the OFDM carrier wave regional signal that FFT portion 28A, 28B are exported is also the same with above-mentioned OFDM symbol area signal, becomes the complex signal that contains real axis composition (I channel signal) and imaginary axis composition (Q channel signal).
The OFDM carrier wave regional signal that is made of a plurality of different carrier signal data that FFT portion 28A, the 28B of A system and B system exported is distinguished into carrier wave unit in synthetic portion 29, and is carried out the synthetic of the same carrier wave that is suitable for respectively in each system.
Afterwards, this composite signal is finished the error correcting unit 30 of the error correction that decoding or reed-solomon symbol (Reed-Solomon symbol) wait, the signal after the error correction is carried out the mpeg decode portion 31 of MPEG expansion, the audio frequency and video separated part 32 of isolating vision signal and audio signal from the MPEG spread signal, the video decode portion 33 of decoding processing that carries out vision signal and the audio decoder portion 34 etc. that carries out the decoding processing of audio signal through carrying out the Vito, is exported among the figure the not audio frequency and video reproducing unit (perhaps video and audio recording portion) of demonstration.
Here, (n, m) the OFDM carrier wave regional signal exported of the 28A of FFT portion of expression A system is with Zb (n, m) the OFDM carrier wave regional signal exported of the 28B of FFT portion of expression B system with Za.
The schematic diagram of the OFDM carrier wave regional signal that Fig. 2 is exported for FFT portion 28A, 28B.Among this figure, transverse axis is represented the frequency of carrier wave, has marked a series of carrier index (n) along this transverse axis.In addition, the longitudinal axis is represented symbol (time), has marked a series of OFDM symbol number (m) along this longitudinal axis.Black circle mark represents to have the carrier wave that is called synchronizing signal (discrete navigation signal or SP signal) of known power and phase place, encloses the carrier wave that mark represents not insert synchronizing signal in vain.As can be seen from this figure, synchronizing signal, with ratio quilt (jumpily) insertion discretely of 1 of insertion in axial 12 carrier waves of frequency, and on each symbol of time-axis direction, to 3 carrier waves of frequency axis direction skew.
The position of any carrier wave can both be represented by the symbol number (m) and the intersecting point coordinate of carrier index (n).A carrier wave that is come by enclosed with dashed lines among the figure for example, its n=8, m=3, therefore in this case, the OFDM carrier wave regional signal that the 28A of FFT portion of A system is exported is Za (n, m) → Za (8,3), same, the OFDM carrier wave regional signal that the 28B of FFT portion of B system is exported is Zb (n, m) → Zb (8,3).
Fig. 3 A is the block diagram of the synthetic portion 29 of the composite signal of the output signal of the output signal that generates the A system and B system.Among this figure, synthetic portion 29 has the 1st carrier filter the 35, the 2nd carrier filter 36, difference arithmetic unit 37, sign inversion device the 38, the 1st multiplier the 39, the 2nd multiplier 40 and adder 41.
Fig. 3 B is the movement concept figure of the 1st carrier filter 35 and the 2nd carrier filter 36.The rectangle frame of the prolate among figure medelling is respectively represented the 1st carrier filter 35 and the 2nd carrier filter 36, the carrier wave of hypographous circle diagrammatic representation process object, and black loop graph shape represents to be positioned at the synchronizing signal of its front and back.
Now, 2 synchronizing signal (SPa (n-i of the front and back of any carrier index (n) of the 1st carrier signal 35 by being positioned at optional sign numbering (m), m) with SPa (n+j, m)) known transmission characteristic information (signal power and phase place), obtain process object carrier wave (Za (n, the presumed value of transmission characteristic m)) (Za (n, m) ').Equally, 2 synchronizing signal (SPb (n-i of the front and back of any carrier index (n) of the 2nd carrier signal 36 by being positioned at optional sign numbering (m), m) with SPb (n+i, m)) known transmission characteristic information, obtain process object carrier wave (Zb (n, the presumed value of transmission characteristic m)) (Zb (n, m) ').Here, the signal of " a " expression A system, the signal of " b " expression B system, in addition, the interval (carrier number) between " i " and " j " expression process object carrier wave and the synchronizing signal before and after it.
Calculus of differences is carried out in 37 pairs the 1st carrier filters 35 of difference arithmetic unit and the 2nd carrier filter 36 output separately.Also promptly, calculate (Za (n, m) '-Zb (n, m) ').If this operation result is that (n, m), (n, symbol m) carry out oppositely 38 couples of K of sign inversion device K, and (n (also is K (n, inverse m)) output as this sign inversion result m) with Ki.The 1st multiplier 39 calculate " Za (and n, m) * K (n, m) ", the 2nd multiplier 40 calculate " Zb (and n, m) * Ki (n, m) ".Last by the operation result addition of adder 41 with the 1st multiplier 39 and the 2nd multiplier 40, (n m), exports to the error correcting unit 30 of back as the composite signal Zd of the output signal of output signal of synthesizing the A system and B system with this addition result.(n m) carries out the Vito and finishes error correction processing such as decoding or reed-solomon symbol 30 couples of composite signal Zd that exported of error correcting unit.
Fig. 4 is the movement concept figure of each circuit in n the circuit of synthetic portion 29.Among the figure, and Za (n, m) ' be the output signal of the 1st carrier filter 35, Zb (n, m) ' be the output signal of the 1st carrier filter 35.(n m) is obtained by difference arithmetic unit 37 the difference value K of these signals, and in addition, (n m) is obtained by sign inversion device 38 the sign inversion value Ki of this difference value.
By the 1st multiplier the 39, the 2nd multiplier 40 and adder 41, calculate Zd (n, m)=Za (n, m) * K (n, m) }+Zb (n, m) * Ki (n, m) }, (n m) exports to the circuit of back with this operation result Zd.
Because some influence in the transmission way, for example the signal Za of A system (n, m) with the signal Zb of B system (n produces after the difference between m), this difference just appear at K (n, m) and Ki (n, m) in.Like this, the corrected value by using the above-mentioned difference of expression " K (and n, m) with Ki (n, m) ", proofread and correct the A system signal Za (n, m) with the signal Zb of B system (n, m), just can access and not have the composite signal of above-mentioned difference Zd (n, m).
Therefore, in this execution mode, as mentioned above, owing to synthesize processings, therefore can not be accompanied by the losing of information (carrier wave) of the ofdm signal that synthesizes processing with the information unit (carrier wave unit) of each OFDM.And, because of for all carrier waves that comprise the carrier wave that does not insert synchronizing signal, be correlated with to synthesize and handle, improve receiving quality (C/N) so can reduce error rate, improve the receptivity of the OFDM receiving system that uses diversity.
Fig. 5 A and Fig. 5 B are the effect key diagram of present embodiment.
Among Fig. 5 A, the longitudinal axis is the signal level of A system reception ripple and B system reception ripple, and transverse axis is a frequency.Shown among Fig. 5 A in the OFDM receiving system that uses diversity, the A system that the A system is received receives ripple, the B system received with the B system receives these two signals that system is received of ripple, carrying out FFT in each system handles, FFT in this each system is handled a plurality of different signal data that carrier wave constituted afterwards, in synthetic portion 29, divide into carrier wave unit, and adapt to synthetic resulting composite wave according to the identical carrier wave in each system.
Among Fig. 5 A, each received signal of A system and B system is subjected to various interference in the transmission way, the decline (with reference to the hollow arrow K among the figure, L, M) of signal level has consequently taken place in different frequencies, but in the present embodiment, distinguish with each carrier wave and adapt to synthetic the processing by the signal data after in synthetic portion 29, the FFT in each system being handled, the same carrier wave that obtains in each system is peaked signal often, is similar to the characteristic with level and smooth spectrum distribution that sends ripple thereby can access.
In addition, among Fig. 5 B, the longitudinal axis is BER (bit error rate), and transverse axis is the C/N ratio.
Fig. 5 B is for illustrating under the situation of multipath state the error rate that the obtains expecting (schematic diagram of BER ≈ 2 * 1E-04) necessary C/N ratios.Dotted line is represented the Gaussian noise of a ripple, and the BER characteristic of former mode (carrying out the mode based on the diversity of time zone signal) is represented in double dot dash line, and solid line is represented the BER characteristic of present embodiment (carrying out the mode of the diversity of frequency field).
Can learn by Fig. 5 B, for the error rate that obtains expecting (BER ≈ 2 * 1E-04), former mode needs the C/N ratio of about 15dB, present embodiment then only needs the C/N ratio of about 9.5dB.Also promptly, the C/N ratio that present embodiment only need obtain comparing with former mode the about 9.5dB that has reduced 5.5dB just can carry out good reception.
According to the present invention, with a plurality of different formed signal data of carrier wave that FFT exported, in synthetic portion 29, be that unit is distinguished with the carrier wave, therefore adapt to syntheticly according to the same carrier wave in each system, can provide a kind of OFDM receiving system and OFDM method of reseptance that has reduced error rate and improved the use diversity of receiving quality (C/N).
Claims (3)
1. OFDM receiving system (23) that uses diversity, receive message spacing become a plurality of carrier waves in the given bandwidth and carries out that quadrature modulation generated, be the orthogonal frequency-division multiplex singal of unit of transfer with the symbol, it is characterized in that:
Have:
The 1st converting means (28A), it is used for handle by the above-mentioned ofdm signal that the 1st antenna (24A) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
The 2nd converting means (28B), it is used for handle by the above-mentioned ofdm signal that the 2nd antenna (24B) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
Difference value arithmetic unit (37), it calculates the difference value between the signal that a plurality of synchronizing signal generated that is contained in the signal that a plurality of synchronizing signal generated that contained in the carrier wave regional signal by above-mentioned the 1st converting means conversion and the carrier wave regional signal by above-mentioned the 2nd converting means conversion;
Reciprocal computing device (38), it calculates the inverse of the difference value that is calculated by above-mentioned difference value arithmetic unit;
The 1st multiplier (39), it multiplies each other the difference value that the carrier wave regional signal and the above-mentioned difference value arithmetic unit of the conversion of above-mentioned the 1st converting means institute are calculated;
The 2nd multiplier (40), the reciprocal multiplication of the difference value that it is calculated the carrier wave regional signal and the above-mentioned reciprocal computing device of the conversion of above-mentioned the 2nd converting means institute; And
Adder (41), it is with the multiplication result addition in multiplication result in above-mentioned the 1st multiplier and above-mentioned the 2nd multiplier.
2. OFDM receiving circuit (23) that uses diversity, receive message spacing become a plurality of carrier waves in the given bandwidth and carries out that quadrature modulation generated, be the orthogonal frequency-division multiplex singal of unit of transfer with the symbol, it is characterized in that:
Have:
The 1st translation circuit (28A), it is used for handle by the above-mentioned ofdm signal that the 1st antenna (24A) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
The 2nd translation circuit (28B), it is used for handle by the above-mentioned ofdm signal that the 2nd antenna (24B) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
Difference value computing circuit (37), it calculates the difference value between the signal that a plurality of synchronizing signal generated that is contained in the signal that a plurality of synchronizing signal generated that contained in the carrier wave regional signal by above-mentioned the 1st translation circuit conversion and the carrier wave regional signal by above-mentioned the 2nd translation circuit conversion;
Computing circuit (38) reciprocal, it calculates the inverse of the difference value that is calculated by above-mentioned difference value computing circuit;
The 1st mlultiplying circuit (39), it multiplies each other the difference value that the carrier wave regional signal and the above-mentioned difference value computing circuit of the conversion of above-mentioned the 1st translation circuit institute are calculated;
The 2nd mlultiplying circuit (40), the reciprocal multiplication of the difference value that it is calculated the carrier wave regional signal and the above-mentioned computing circuit reciprocal of the conversion of above-mentioned the 2nd translation circuit institute; And
Add circuit (41), it is with the multiplication result addition in multiplication result in above-mentioned the 1st mlultiplying circuit and above-mentioned the 2nd mlultiplying circuit.
3. OFDM method of reseptance (23) that uses diversity, receive message spacing become a plurality of carrier waves in the given bandwidth and carries out that quadrature modulation generated, be the orthogonal frequency-division multiplex singal of unit of transfer with the symbol, it is characterized in that:
Have:
The 1st shift step (28A), it is used for handle by the above-mentioned ofdm signal that the 1st antenna (24A) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
The 2nd shift step (28B), it is used for handle by the above-mentioned ofdm signal that the 2nd antenna (24B) that receives above-mentioned ofdm signal is received, and is transformed into the carrier wave regional signal of above-mentioned symbolic unit;
Difference value calculation step (37), it calculates the difference value between the signal that a plurality of synchronizing signal generated that is contained in the signal that a plurality of synchronizing signal generated that contained in the carrier wave regional signal by above-mentioned the 1st shift step conversion and the carrier wave regional signal by above-mentioned the 2nd shift step conversion;
Calculation step (38) reciprocal, it calculates the inverse of the difference value that is calculated by above-mentioned difference value calculation step;
The 1st multiplication step (39), it multiplies each other the difference value that the carrier wave regional signal and the above-mentioned difference value calculation step of the conversion of above-mentioned the 1st shift step institute are calculated;
The 2nd multiplication step (40), the reciprocal multiplication of the difference value that it is calculated the carrier wave regional signal and the above-mentioned calculation step reciprocal of the conversion of above-mentioned the 2nd shift step institute; And
Addition step (41), it is with the multiplication result addition in multiplication result in above-mentioned the 1st multiplication step and above-mentioned the 2nd multiplication step.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2003367193 | 2003-10-28 | ||
JP2003367193A JP3952200B2 (en) | 2003-10-28 | 2003-10-28 | OFDM receiving apparatus using diversity, OFDM receiving circuit using diversity, and OFDM receiving method using diversity |
Publications (2)
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CN1612515A CN1612515A (en) | 2005-05-04 |
CN1287544C true CN1287544C (en) | 2006-11-29 |
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CN200410087904.9A Expired - Fee Related CN1287544C (en) | 2003-10-28 | 2004-10-27 | Device for using OFDM diversity reception, OFDM receiving circuit and OFDM reception method |
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US (1) | US7424073B2 (en) |
EP (1) | EP1528741B1 (en) |
JP (1) | JP3952200B2 (en) |
CN (1) | CN1287544C (en) |
DE (1) | DE602004011874T2 (en) |
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JP4682684B2 (en) * | 2005-04-28 | 2011-05-11 | パナソニック株式会社 | Digital signal receiver |
EP1909423A4 (en) * | 2005-07-27 | 2011-04-20 | Pioneer Corp | Receiver apparatus |
CN101461160A (en) * | 2006-06-12 | 2009-06-17 | 松下电器产业株式会社 | Receiver |
KR101424069B1 (en) * | 2007-06-01 | 2014-08-14 | 삼성전자주식회사 | OFDM transmitting/receiving apparatus and method |
JP4823165B2 (en) * | 2007-08-07 | 2011-11-24 | 株式会社東芝 | OFDM receiver |
CN101874372A (en) * | 2007-11-28 | 2010-10-27 | 松下电器产业株式会社 | Diversity reception device, diversity reception method, semiconductor integrated circuit, and receiver |
US20090237209A1 (en) * | 2008-03-20 | 2009-09-24 | Brian William Seal | Communicating keychain |
US8249205B2 (en) * | 2009-11-05 | 2012-08-21 | Visteon Global Technologies, Inc. | HD radio diversity receiver with shared processing paths |
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KR100224863B1 (en) | 1997-08-20 | 1999-10-15 | 윤종용 | Equalizing method for ofdm receiver and equalizer |
US6327314B1 (en) * | 1998-04-01 | 2001-12-04 | At&T Corp. | Method and apparatus for channel estimation for multicarrier systems |
US5973642A (en) * | 1998-04-01 | 1999-10-26 | At&T Corp. | Adaptive antenna arrays for orthogonal frequency division multiplexing systems with co-channel interference |
JP2000036801A (en) | 1998-07-21 | 2000-02-02 | Nec Corp | Diversity receiver |
US6654429B1 (en) * | 1998-12-31 | 2003-11-25 | At&T Corp. | Pilot-aided channel estimation for OFDM in wireless systems |
JP2001285156A (en) | 2000-03-29 | 2001-10-12 | Clarion Co Ltd | Diversity receiver |
JP3678119B2 (en) * | 2000-06-01 | 2005-08-03 | 株式会社デンソー | OFDM communication system and base station and terminal used in the communication system |
JP4033374B2 (en) | 2001-03-09 | 2008-01-16 | 日本放送協会 | OFDM signal relay device |
KR100510434B1 (en) * | 2001-04-09 | 2005-08-26 | 니폰덴신뎅와 가부시키가이샤 | OFDM signal transmission system, OFDM signal transmission apparatus and OFDM signal receiver |
JP4496673B2 (en) | 2001-06-07 | 2010-07-07 | 株式会社デンソー | OFDM transceiver |
JP3782330B2 (en) | 2001-09-14 | 2006-06-07 | 富士通株式会社 | OFDM receiving method and OFDM receiving apparatus |
US7173990B2 (en) * | 2001-12-27 | 2007-02-06 | Dsp Group Inc. | Joint equalization, soft-demapping and phase error correction in wireless system with receive diversity |
JP3691449B2 (en) * | 2002-03-25 | 2005-09-07 | 三洋電機株式会社 | Diversity circuit and diversity receiver including the circuit |
-
2003
- 2003-10-28 JP JP2003367193A patent/JP3952200B2/en not_active Expired - Fee Related
-
2004
- 2004-10-26 US US10/973,860 patent/US7424073B2/en not_active Expired - Fee Related
- 2004-10-27 DE DE602004011874T patent/DE602004011874T2/en active Active
- 2004-10-27 CN CN200410087904.9A patent/CN1287544C/en not_active Expired - Fee Related
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DE602004011874D1 (en) | 2008-04-03 |
JP3952200B2 (en) | 2007-08-01 |
DE602004011874T2 (en) | 2009-02-19 |
JP2005136471A (en) | 2005-05-26 |
CN1612515A (en) | 2005-05-04 |
EP1528741B1 (en) | 2008-02-20 |
US7424073B2 (en) | 2008-09-09 |
US20050111600A1 (en) | 2005-05-26 |
EP1528741A1 (en) | 2005-05-04 |
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